The present invention relates generally to a screen printing machine, and more particularly to a screen printing machine which is capable of printing wide webs, such as carpets, rugs and the like.
It is well known to use screen printing machines for printing carpets, rugs and similar materials. It is also known to use a flexible printing screen which is trained about rollers and driven in rotation by the same, and which serves to print onto a workpiece such as a carpet, rug or the like. Difficulties have been encountered in prior-art machines of this type because if either the printing screen should shift axially of the rollers, or the web or workpiece -- which of course advances transversely of the axis of the rollers -- should shift axially of the rollers and thus with reference to the printing screen, the rollers must be readjusted in order to obtain a precise printing effect. This is particularly true in the case of multi-color printing, for instance four color printing, where it is necessary to constantly readjust the rollers in order to assure that the printing carried out with the latest color will register with the printing that has already been previously carried out with one or more preceding colors. The constant readjustments which are required for the rollers mean, of course, that the lower run of the printing screen is also adjusted, that is the run which is juxtaposed with the workpiece. It is self-evident to those with skill in the art that this is disadvantageous.